Voltage Sag Severity Assessment Method Considering Multi-dimension Characterization

Abstract

With development of new advanced technology, many new types of equipment are sensitive to voltage sags. Since lots of characteristics are ignored in existing characterization methods, their voltage sag severity assessment is invalid for some new types of equipment. To improve this situation, this paper proposes a severity assessment method based on voltage sag multi-dimension characterization. To overcome the drawbacks in existing methods, the multi-dimension characterization method is proposed to obtain more information from recorded sag waveform. A pattern bank of sensitive characteristics is established with a set of typical tolerance curves. Then, similarity between multi-dimension characteristics and sensitive characteristic set is utilized to determine membership function of severity assessment. Finally, field measured waveforms are used for validation. Results show that the proposed method has higher accuracy than existing methods, especially when the information of customer side is limited.